Course Hero Logo

Chem 122 Lab Report #4.pdf - pKa and Ka Determination of an...

Course Hero uses AI to attempt to automatically extract content from documents to surface to you and others so you can study better, e.g., in search results, to enrich docs, and more. This preview shows page 1 - 3 out of 9 pages.

pKa and Ka Determination of an Unknown WeakAcidExperiment #: 4Chem 122 Lab: Section #: 11Date: 03/05/2020I certify that I have read and have approved the submission ofthis group lab report:PrintSignatureTeam Member 1Paige FodeTeam Member 2Paul JosephTeam Member 3Trevor GearmanTeam Member 4Darshika Pokhrel
AbstractA titration of KHP, an acidic salt, was performed using a strong base in sodium hydroxide. Usingthe titration method. Phenolphthalein indicators helped us identify the pink color and gave us thefinal and initial volumes which gave us the final volume. Vernier Systems pH probe is used tomonitor and graph titration process, which helps determine constants pKa and ka. Using all ourinformation we were able to calculate final molarity m1v1=m2v2.Introduction:There are two experimental objectives for this experiment. One the first is todetermine the pKa and Ka of a weak acid via titration curve. Second objectives is to study therelative strengths of weak acids.Acidity is a key concept in determining pKa and ka and in General Chemistry. Acid isdefined as a compound that can donate a hydrogen ion to other compounds. There are weak acidand stronger acid.The stronger the acid, when a compound can very easily donate their proton.The acid that was used in this experiment is weak acid. It is defined as when dissolved in watersome of the acid molecules will donate a proton to water creating a hydronium ion. Titration of aweak acid with a strong base (NaOH) can be applied to determine the molecular weight and theacidity constant of the weak unknown acid in H2O. All the unknown acids in this experiment aremonoprotic.Experimental ProcedureFor one part of this experiment a titration was performed. First 500 mL of 0.1 M NaOH wasprepared and we call this standardization. Some of the NaOH solution was placed in the buret tothe 0 mL mark on the buret.Three samples of KHP weighing between 0.2 and 0.3 grams were taken and were placedinto a flask. Then the KHP was dissolved in almost 50 mL of distilled water and after two dropsof phenolphthalein indicator were added to the KHP solution.The initial volume on the buret is recorded, so for the first trial the initial volumerecorded should be 0 mL. For the first KHP sample, NaOH was added 1-2 mL at a time whileswirling the flask constantly. Continue to do this until the KHP solution turns a light pink color

Upload your study docs or become a

Course Hero member to access this document

Upload your study docs or become a

Course Hero member to access this document

End of preview. Want to read all 9 pages?

Upload your study docs or become a

Course Hero member to access this document

Term
Spring
Professor
NoProfessor
Tags

Newly uploaded documents

Show More

Newly uploaded documents

Show More

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture